It seems that every week, I learn about yet another Facebook privacy concern or glitch. Today, Adi Kamdar of EFF made me aware of another one:

Facebook Messages has a feature that tells you when a chat recipient has seen a message. This “read receipt” is, in true Facebook fashion, both nifty and unsettling. And it brings with it tons of potential for abuse. Unfortunately, there’s no built-in method to opt out.

Facebook’s privacy interface has undergone change upon change, yet some needed controls simply don’t exist—and these days consumer privacy depends heavily on control. Luckily, the developers over at Crossrider have an extension, Chat Undetected, that disables the read receipt feature. The extension is available for Chrome, Firefox, Internet Explorer, and Safari.